Plasma is a collection of charged particles which is macroscopically neutral over a volume that is small compared to its dimensions. Nuclear fusion research has been most actively pursued by the use of hot plasma. In principle, the motion of each particle can be determined from Newton’s second Law and the electrostatic force that each particle exerts on all other particles. The magnetic plasma method must be heated and confined in order to utilize the nuclear fusion energy released from the plasma with a high temperature. The plasma consists of charged particles. Charged particles cannot cross magnetic field lines, but rotate around the lines. There is the outline of the idea of magnetic field lines in which to confine the plasma. In Figure 1 as shown, elliptic torus of fusion design cross-section, the particle drifts in the presence of a purely torodial magnetic field. The B magnetic gradient and curvature drifts produce a charge separation, which, in turn, produces an electric field with an associated outward drift for both ions and electrons and loss of confinement. In the geometry, a torus is a surface of motion generated by revolving a circle in 3D space.

When the magnetic field changes slowly, the magnetic moment is conserve. Therefore, if B is increased, mv²/2 = μB is also increased and the particles are heated. This kind of heating is called adiabatic heating. This solution shows that the guiding center motion consists of usual ExB drift and the new drift along E. Plasmas can be described as magnetohyrodynamic two fluids of ions and electrons with mass densities ρ_mi, ρ_me, charge density ρ, current density j, flow velocities Vi, Ve and pressures Pi, Pe.

The number of ions dNi in a small phase space volume,

Magnetohydrodynamic (MHD) equations are the following;

In the Monte Carlo Method, random numbers are generated for each element and for each random number, an examination is conducted in order to determine if the system obtained or not. There are practical manual methods for the generation of the Random numbers as well as a number of mathematical methods. According to the status of the analyzed system, there are practical methods like tossing dices, heads or tails or bingo, as will be understood from the name Monte Carlo. MCNP code includes Monte Carlo simulation and physics and mathematics subjects that have nuclear characteristics including certain subjects. During particle transport, neutrons, photons and electrons are used. MCNP in fact is a code that has been generalized by the Monte Carlo group in los-alamos labs for theoretic physics [5] [6] [8] [9] . MCNP possesses a general block that contains approximately 40,000 lines of Fortran and 1000 lines C source coder that includes interpretations and a general block that applies the program Monte Carlo Simulation is used in the simulation of some physical and mathematical systems. Generally, it is used for analyzing the effect of the random variables on the system and operates mostly with an algorithm that generates random numbers for the variables. The variables for which Monte Carlo simulation is to be conducted may be generated in a way that will suit a specific statistical distribution [4] [8] - [11] . The opposite of complementary probability distribution function (CDF) is used. The random numbers that are uniformly generated by the computer at a certain interval (0 − 1) may easily be transformed to any kind of distribution using the opposite of the

The design of 3d torus of fusion reactor the plasma and the blanket lithium around the plasma and the structural element that contains U and Th are shown in Figure 2.

The neutrons that are radiated as a result of the fusion reactions that occur at the plasma are captured at the blanket by uranium, thorium and the production of fissile fuel is provided. It is not possible to combust U²³⁸ in most reactors because the fusion impact incision is very low and the activation energy is too high. Th²³² also is not an appropriate material for combustion [12] [14] [15] . Monte Carlo Random Simulation (MCRS), models the probable systems based on randoms. It is possible to calculate the integrals with the Monte Carlo Method through phase transitions [5] [6] [8] - [10] .

f(x) function at the [a, b] interval is considered : din order to show the size of the integral, quadratic total demonstration of such an integral shall be,

. According to the Average value theorem, the integral of a

f(x) function at [a, b] interval is equal to the area of the rectangle which is drawn at the average value of the function as seen on Figure 2; then average value is multiplied by (b − a) and the integral is calculated.

If the arithmetic average of N number of dots that are chosen randomly at the, [a, b] interval of the function is calculated, it will be: So, reaches the Monte Carlo integration formula:, the dots have not been arranged with equal intervals, they are chosen

completely randomly. As number N increases, the numeric calculation gets closer to the value of the I integral. But this approach is not as fast as expected. This slow approach is a general characteristic of the random methods. Here, according to the result that is provided without proof, the margin of error decreases slowly as [6] [11] [16] .

Neutron tracking refers to the process of simulating the movement of a single neutron through the different material regions of the geometry. The shortest length of path that the neutron makes between the points of interaction is called a track. The track can also be cut short by a material boundary surface located between the two points. The entire set of tracks made from the initial emission to the final absorption or escape is called a neutron history.

The number of neutron histories is hence equal to the total number of emitted source neutrons. The basis of the simulation process is the sampling of the free path length between two collision points. Figure 4 shows the estimation of Monte Carlo random errors of number of neutron histories.

A commercial fusion reactor must have a tritium breeding ratio of (TBR) > 1.05 to be self sustaining. Figure 5 shows the variation of total fissile material production speed for Flibe due to the ratio of UF4 and ThF4. As expected, the TBR decreases with increased heavy metal content. Tritium self sufficiency has been maintained in the range of molten salt mixtures (Flibe with up to 10% - 50% UF4) are shown results in Table 1. These molten salt mixtures would make the highest level of fissile breeding possible. Uranium has a higher neutron multiplication than thorium. On the other hand, the excess tritium gain for external fusion reactors is reduced significantly with the introduction of heavy metal into the coolant. When the fast and slow neutrons interaction with the lithium blanket, Li and T are produced as shown [15] [21] [22] ;

where, M is the energy multiplication factor, is fissile fuel production ratio, is ratio of total fission and υ is total number of fusion neutron. In Figure 5 as shown fissile fuel breeding are done fissile fuel breeding rates of ²³⁸U(n, ɣ)²³⁹Pu and ²³² Th (n, ɣ)²³³U increase almost linearly with increased heavy metal content.